vaalpens
Member
- Joined
- Aug 14, 2014
- Messages
- 2,618
As you all know, RMR is now making a 9mm 124gr FMJ FN bullet. Late on Wednesday they became available and I put in a order for 500 for evaluation in 357sig.
On Saturday I received the package after very quick processing from RMR. Thanks RMR! This is what they look like.
As always when I receive a bullet I haven't loaded before in 357sig, these are the steps I follow:
-Take some measurements
-Calculate to see if they will fit in 357sig
-Based on the calculation decide on a COL
-Load some dummy rounds
-Verify the fit to ensure start of ogive is outside the mouth of the case
-Do a plunk test
-Do a setback test by cycling the dummy rounds through the gun
-Do a bathroom scale test
-Decide on the first set of loads
-Create the first loads
-Evaluate the loads
Let's start with the measurements:
Length of 10 bullets were .5525" (4), .5510" (1), .5535" (3), .5550 (2)
Diameter of all 10 were .3555" with a few floating to .3560" when I removed my hand from the caliper (excellent for 357sig)
Weight: Most of them were just below 124gr, with one over 124gr
Based on my calculation and the shape of the bullet, it seems that I could maybe load it with a COL of 1.135", but a 1.140" COL will probably be better with a sliver of breathing room. Based on this calculation I will classify this bullet as a 9mm bulle, that will also fit in 357sig. For me a 357sig bullet is one I have the flexibility to load it with a COL of 1.125" to 1.135" with ease.
I then created my dummy rounds with a COL of 1.140":
The next step was to verify that my COL/ogive calculation was correct. From this photo you can see that there is a visible gap, which means the ogive starts outside the case mouth:
My next steps will be the plunk and battery of setback tests and I will post an update as soon as I have performed the tests.
So far I am impressed with the bullets, especially the consistent diameter. When I seated the dummy rounds, I could feel this was not something that just slipped in, but there were some tension. The neck tension on these seemed to be very good, but the setback test will provide the final answer.
On Saturday I received the package after very quick processing from RMR. Thanks RMR! This is what they look like.
As always when I receive a bullet I haven't loaded before in 357sig, these are the steps I follow:
-Take some measurements
-Calculate to see if they will fit in 357sig
-Based on the calculation decide on a COL
-Load some dummy rounds
-Verify the fit to ensure start of ogive is outside the mouth of the case
-Do a plunk test
-Do a setback test by cycling the dummy rounds through the gun
-Do a bathroom scale test
-Decide on the first set of loads
-Create the first loads
-Evaluate the loads
Let's start with the measurements:
Length of 10 bullets were .5525" (4), .5510" (1), .5535" (3), .5550 (2)
Diameter of all 10 were .3555" with a few floating to .3560" when I removed my hand from the caliper (excellent for 357sig)
Weight: Most of them were just below 124gr, with one over 124gr
Based on my calculation and the shape of the bullet, it seems that I could maybe load it with a COL of 1.135", but a 1.140" COL will probably be better with a sliver of breathing room. Based on this calculation I will classify this bullet as a 9mm bulle, that will also fit in 357sig. For me a 357sig bullet is one I have the flexibility to load it with a COL of 1.125" to 1.135" with ease.
I then created my dummy rounds with a COL of 1.140":
The next step was to verify that my COL/ogive calculation was correct. From this photo you can see that there is a visible gap, which means the ogive starts outside the case mouth:
My next steps will be the plunk and battery of setback tests and I will post an update as soon as I have performed the tests.
So far I am impressed with the bullets, especially the consistent diameter. When I seated the dummy rounds, I could feel this was not something that just slipped in, but there were some tension. The neck tension on these seemed to be very good, but the setback test will provide the final answer.